Stoppers
Stoppers, also known as bungs, are used to give an airtight seal to laboratory flasks and test tubes by fitting tightly inside the neck of the container and preventing material from spilling. Stoppers can be made of glass, cork, rubber, or silicone. They are typically designed with a conical shape, but straight, flanged, and tapered options are also available.
Stoppers are the preferred choice for many applications requiring a tighter seal or a greater degree of chemical resistance. They also provide a good seal when a solution needs to be shaken or mixed without spilling. Stoppers are generally cylindrical in shape and have a tapered bottom end. They may be marked with a stopper number or size on the top and bottom diameters of the stopper. Sizing can vary among manufacturers.
Stoppers are available in a solid design or with holes known as positions placed in the top. Positions allow easy access to the material contained in the sealed vessel by pipettes, tubing, or other equipment without full removal of the stopper.
What Types of Stoppers Are Available?
• Turnover stoppers have external serrations to create an excellent internal seal combined with a flexible turnover sleeve that folds down over the container’s neck to create a double seal
• Serum bottle or vial stoppers have two or three legs with external serrations or straight sides and a flanged top to create an airtight seal
• Straight bromobutyl plug-type stoppers provide a maximum seal for vials and serum bottles with a straight-wall glass finish
• Ultra-pure, straight bromobutyl plug-type stoppers provide high chemical purity and low gas permeability. They offer excellent performance during freeze drying processes such as lyophilization, where stoppers must remain stable during transfer and sublimination phases
• Silicone recessed septa stoppers are non-toxic and have external serrations to create an effective internal seal
West Pharmaceutical Services Inc 20MM SERUM/4432/50 GY 1000/PK
NC3377503 20MM SERUM/4432/50 GY 1000/PK
Hach Company Silicone Stopper, with 9.5 mm Hole, #8
For Use with the Xenosep Oil and Grease Apparatus. 1/pk
Chemglass Life Sciences Silicone Plug Stoppers, 9mm
Microcarrier spinner flasks promote optimal growth of suspension and microcarrier cultures. Indented bottoms, 100mL thru 1000mL, prevent accumulation of microcarrier beads under the impeller paddle. Please Note: The 6L and 8L Versions Do Not Have Dimpled Bottoms. The complete system includes a flask with two angled sidearms and a PTFE paddle with glass shaft that adjusts trough the compression fitting in the cap.
Accuflow Systems Saint-Gobain Versilic Silicone Stopper, 31D, 25.9x32.0x30.0 mm
Versilic silicone stopper designed to provide a secure, chemical-resistant seal for laboratory and bioprocess vessels. Platinum-cured silicone offers low extractables and broad chemical compatibility; folding-skirt geometry ensures reliable sealing on glass and plastic containers. Commonly used in bioprocessing, analytical, and general laboratory closures.
- Platinum-cured silicone for low extractables and biocompatibility.
- Folding skirt geometry for a secure seal on glass and plastic vessels.
- Dimensions: top 25.9 mm, bottom 32.0 mm, height 30.0 mm.
- Size designation: 31D.
- Pack quantity: 10 per pack.
Accuflow Systems Saint-Gobain Silicone Stopper, Sani-Tech, 1.256 x 1.041 in, Autoclavable
Autoclavable biopharmaceutical-grade platinum-cured silicone stopper engineered for vessel and bottle sealing. The stopper resists cracking and particle migration, and is compatible with common laboratory sterilization methods.
- Platinum-cured silicone.
- Dimensions A x B x H: 1.256 x 1.041 x 0.915 in (31.9 x 26.4 x 23.2 mm).
- Volume: 0.947 in³ (15.52 cm³).
- Weight: 0.040 lb (18.14 g).
- Sterilization: autoclavable; radiation up to 2.5 Mrad (25 kGy); ethylene oxide.
- Compliance: tested to USP Class VI and meets FDA 177.2600 criteria.
- Manufacturing: lot traceability and ISO 9001 production available for custom options.
- Typical applications: carboys, solution and media bottles, process and laboratory apparatus.
Cole-Parmer High-purity silicone stopper, size 8 (41D) Pack of 5
Translucent silicone stoppers are especially suited for procedures demanding high purity, such as tissue culture work and food science applications. Food-grade quality stoppers are nontoxic, chemically inert, and resist particle buildup. Withstand repeated sterilization, as well as temperatures from –76 to 392°F (–60 to 200°C). Peak at 428°F (220°C). European size (DIN no.) is noted on stopper. FDA compliant. Autoclavable.
Uline Silicon Rubber For Foot-Operated Extra-Long Impulse Sealer - 30"
Silicon Rubber For Foot-Operated Extra-Long Impulse Sealer-30IN
Foxx Life Sciences Borosil® Solid Penny Head Glass Stopper with Interchangeable Ground Joint 14/23, 20/CS
Borosil® Solid Penny Head Glass Stoppers are with Interchangeable Ground Joint and can be used with Volumetric Flask of 5645, 5647 families or for other suitable joints. Manufactured with low extractable quality grade USP Type I, 3.3 Borosilicate Glass confirming to ASTM E438 Class A requirements. Available in sizes of 7/16 to 55/54. In collaboration with Borosil Glass Works, Foxx Life Sciences is proud to bring the outstanding quality of Borosil® Type 3.3 Borosilicate glassware to North America for the first time. Manufactured from the same USP Type I, Borosilicate glass that North American scientists have come to trust, Borosil® Laboratory Glassware offers unparalleled mechanical strength, clarity, and reliability at competitive prices. And thanks to a unique annealing process, Borosil® Glassware is stress-free and incredibly resistant to thermal shock.
Foxx Life Sciences Borosil® Solid Penny Head Glass Stopper with Interchangeable Ground Joint 10/19, 20/CS
Borosil® Solid Penny Head Glass Stoppers are with Interchangeable Ground Joint and can be used with Volumetric Flask of 5645, 5647 families or for other suitable joints. Manufactured with low extractable quality grade USP Type I, 3.3 Borosilicate Glass confirming to ASTM E438 Class A requirements. Available in sizes of 7/16 to 55/54. In collaboration with Borosil Glass Works, Foxx Life Sciences is proud to bring the outstanding quality of Borosil® Type 3.3 Borosilicate glassware to North America for the first time. Manufactured from the same USP Type I, Borosilicate glass that North American scientists have come to trust, Borosil® Laboratory Glassware offers unparalleled mechanical strength, clarity, and reliability at competitive prices. And thanks to a unique annealing process, Borosil® Glassware is stress-free and incredibly resistant to thermal shock.
Ace Glass, Inc. Full-length hollow glass stopper with 45/50 standard taper joint.
Full-length hollow glass stopper with 45/50 standard taper joint.
Ace Glass, Inc. Trap, stopper, vacuum, 40/50, 19mm inner & side tube OD
Trap, stopper, vacuum, 40/50, 19mm inner & side tube OD